Top Loading Bobbin

Many machines now use a drop-in bobbin as per the picture (right).  The bobbin is inserted by removing a cover and inserting into the space below, with the thread pulling off anti-clockwise.  The main advantage of this is that the see-through plastic cover shows when the bobbin thread is running out and it is also slightly more convenient to load.

Front Loading Bobbin

Front loading machines use the more traditional bobbin and bobbin case arrangement; the bobbin is first put into a bobbin case.

This, in turn, is then placed in the machine under a flap on the front, below the presser foot.  This is a system that is tried and tested for very many years.